Sheet associating device having rotary pneumatic separators

ABSTRACT

To feed assorted documents in a predetermined order to an inline conveyor track, individual modular sections of a stationary track having drive rollers for the paper are each provided with a feed throat to which documents from the top of a stack contained in a magazine are fed by a continuously rotating suction drum in which a valve restricts suction to the upwardly moving side while a solenoid valve applies suction only at the time when the supply of a document from the hopper in question is required.

United States Patent Inventor Alan K. Day

lll'ord, England Appl. No. 752,836 Filed Aug. 15, I968 Patented Mar. 30,1971 Assignee The Plessey Company Limited Ilt'ord, England Priority Aug.16, 1967 Great Britain 37,756/67 SHEET ASSOCIATING DEVICE HAVING ROTARYPNEUMATIC SEPARATORS 8 Claims, 7 Drawing Figs.

US. Cl 270/58, 271/27 Int. Cl. B65h 39/02, B65h 3/10 Field of Search270/58, 54; 271/27, 28, 29

[56] References Cited UNITED STATES PATENTS 2,883,189 4/1959 Wilson271/27 3,041,067 6/1962 Fox et a1. 271/27 3,175,821 3/1965 Gibson 270/583,271,024 9/1966 May 271/27 Primary Examiner-Robert W. Michell AssistantExaminer-Paul V. Williams Att0rney-Scrivener, Parker, Scrivener andClark ABSTRACT: To feed assorted documents in a predetermined order toan in-line conveyor track, individual modular sections of a stationarytrack having drive rollers for the paper'are each provided with a feedthroat to which documents from the top of a stack contained in amagazine are fed by a continuously rotating suction drum in which avalve restricts suction to the upwardly moving side while a solenoidvalve applies suction only at the time when the supply of a documentfrom the hopper in question is required.

Patented March 30, 1971 3,572,686

3 Sheets-Sheet 1 Paimd March 30, 1971 3,572,686

3 Sheets-Sheet 2 Patented March 30, 1971 3,572,686

5 Sheets-Sheet 3 FIG .4.

SHEET ASSOGIATING DEVICE HAVING ROTARY PNEUMATIC SEPARATORS Thisinvention relates to sheet conveyor devices, more particularly for thefeeding of sheets of paper and has for an object to provide improvedmeans for supplying a conveyor track with sheets from a number ofseparate magazines or equivalent sources.

According to a broad aspect of the present invention a number of hopperunits are spaced along a conveyor track each hopper unit being equippedwith apparatus for feeding individual sheets from the unit on to thetrack through a delivery throat in a direction and at a speedsubstantially similar to that of the movement maintained on the track,the apparatus with which the hopper unit is equipped being controlled bytiming means programmed in a manner such as to ensure the desired orderof the individual sheets on the track.

The apparatus may comprise a rotatable feed drum having suction ports ina part of its circumference for drawing in use one end of the top sheetaway from a pile of sheets loaded in the hopper unit, suction foot meansagainst which in use the top sheet is normally held by suctionsufficient to resist a ten dency for the sheet to be removed by the drumfrom the pile, and means for at least reducing at the suction footmeans, the suction at a predetermined instant to enable the top sheet tobe withdrawn from the pile as the drum rotates and thereafter deliveredthrough the throat to the conveyor track. The means for at leastreducing the suction at the foot may comprise a valve arrangementoperable for effecting, in accordance with the angular position of thefeed drum, pneumatic coupling between either a suction supply port or acontrol port which may be coupled through valve means either to reducedair pressure or suction source (i.e. a vacuum) or to atmosphere inaccordance with signals provided by the timing means. The valvearrangement may take the form of a rotor disc valve which is drivenmechanically at the same angular velocity as the feed drum so thatduring part of a revolution of the feed drum the suction foot is coupledto the suction supply port and during the rest of the revolution it iscoupled to the control port. The control port is normally coupledthrough the valve means to a vacuum or partial vacuum until a signalinitiated by the timing means causes the valve means to operate tocouple the control port to atmosphere, atmospheric pressure thereafterbeing applied to the suction foot by the rotor disc valve thus removingfrom the top sheet the restraining force afforded by the reduced airpressure at the vacuum foot and allowing the sheet, through furtherrotation of the feed drum, to be carried away from the pile. forsubsequent ejection through the throat on to the conveyor track.

The valve means may comprise a two-way valve which is solenoid operatedin accordance with signals produced by the timing means. When it isrequired to feed a sheet from a selected hopper unit on to the conveyortrack a signal from the timing means causes a two-way solenoid valve tooperate thereby to switch the control port from .vacuum to atmosphere.This operation is preferably completed whilst a portion of the feed drumcircumference having no vacuum ports is adjacent the sheet. As the feeddrum rotates further the vacuum ports in its circumference draw one endof the sheet away from the pile and suction is still applied by thesuction foot at the other end of the sheet causing the sheet to remainon the pile. The drum thus slips aver the end of the sheet which isdrawn away from the pile. As the drum rotates further the rotor discvalve switches portsin the suction foot from vacuum to the control portwhich is now at atmosphere thus relieving from the sheet the restrainingforce previously applied by the suction foot and enabling the sheet tobe carried round initially by the drum alone and then by the drumassisted by a belt drive, the to the throat through which it is ejectedon to the conveyor track.

Sheets from each magazine are fed to separate entry points spacedpreferably at equal intervals along the conveyor track. The rotor discvalves, one of which is associated with each magazine, are preferablyoperated in synchronism, their switching action only being effective forsheet feed purposes if the two-way valve associated with the selectedmagazine is first operated. In this way the time spacing betweensuccessive sheet-feeding operations may be maintained constantindependently of solenoid-operating times and vacuum decay times of thetwo-way valves, since the two-way valve only sets the state of thecontrol port (either to vacuum or to atmosphere) which is actuallysampled by the rotor disc valves as they operate contemporaneously androtate synchronously with the feed drum.

Preferably the hopper unit includes a magazine which may be readilyinserted into and withdrawn from a hopper structure and exchanged foranother magazine when the stock in one magazine is exhausted or when itis desired to change over to different sheet forms. The conveyor trackis preferably arranged above the magazine with the drum arranged overthat end of the sheets in the magazine which faces the rearward end ofthe track, so that after passing over one-half of the circumference ofthe drum this end of each sheet will be ejected first on to the trackthrough a suitably inclined throat to become the leading edge of thesheet during its travel.

Until the magazine in each of-the hopper units are suitably positionedfor sheet feeding the vacuum is automatically cut off. The hopperstructure is arranged to raise a platform at the lower end of the stackof sheets in an inserted magazine until when the uppermost sheet reachesa predetermined level just below the feed drum, which is arranged toswitch on the vacuum and to restart the feed movement when the level hasfallen by a predetermined amount. This will ensure that the top sheet inthe magazine will be reliably picked up by the suction of the drum whenrequired and will avoid the risk of jamming due to pressure between thesurface of the drum, the sheets and the magazine. In order to effectseparation between the top sheet of the stack which has been picked upat one end by the suction foot and the next sheet, an air jet isdirected across the top of the stack to effect this separation andobviate the risk of two sheets being picked up by the drum. Thecontinuation of the movement of each sheet after its delivery to thetrack may conveniently be effected in a conventional way by drivenrollers in the track bed, against which the sheets are resiliently urgedby slightly loaded nondriven contact rollers.

Some exemplary embodiments of the invention will now be described withreference to the accompanying drawings in which:

FIG. 1 is a generally diagrammatic side elevation partly in section ofsheet conveyor apparatus;

FIG. 2A and FIG. 2B are respectively an elevation and sectional view ofa feed drum utilized in the apparatus of FIG. 1;

FIG. 3A, FIG. 3B and FIG. 3C are respectively, an end elevation, a sideelevation partly in section, and the other end elevation of aface-sealing element for use with the feed drum shown in FIG. 2; and

FIG. 4 is a schematic diagram showing the valve arrangement of theapparatus of FIG. 1.

Referring now to FIG. 1 a conveyor track for feeding sheets of paper inthe direction indicated by the arrow A is subdivided into modularlengths abutting at points B, each length being equipped with a numberof continuously driven rollers 2 which project through the upper surfaceof the track 1 and face spring-loaded pressure rollers 3, which arefreely rotatable about their axis and serve to maintain any sheet ofpaper moving along the track in adequate frictional contact with thedriven rollers 2. Parts of the preceding and following modulescorresponding to parts, 1, 2 and 3 have been indicated by the samereference numerals supplemented with a and respectively. Each module 1of the track is further formed with an inclined throat 4 through whichsheets of paper can be fed on to the track and throat 4 of each module 1cooperated with a suction feed drum 5 part of whose circumference isformed with numerous suction ports 6. As shown in FIG. 2A and FIG.2B.the suction ports 6 extend radially from a shallow channel 7 in partof the circumferential surface of the drum 5, to join with suction feedbores 8 which extend axially from a sealing face 9 of the drum. The face9 of the drum cooperates with a stationary generally annular face sealvalve shown in FIG. 3A, FIG. 3B and FIG. 3C. The sealing face 9 of thedrum 5 is urged, by means not shown, against face 11 of the valve 10. Anelongated aperture 12 in the face 11 cooperates with a vacuum feed bore13 which extends from a position on the circumferential face of theannular face seal valve 10. The respective radial positions of thesuction feed bores 8 and the elongated apertures 12 are coincidentallyarranged so that as the drum 5 rotates with respect to the valve 10,suction is applied successively to the bores 8 so that suction isapplied to the drum 5, for about three-quarters of each revolution. Forthe other quarter of the revolution, the elongated apertures cooperatewith a blank portion 14 in the face 9 of the drum 5 having no suctionfeed bores and consequently no suction is applied to the suction ports 6of the drum 5.

Arranged underneath the drum 5 is a hopper device which includes areadily exchangeable magazine 15. This magazine is located in the hopperunit by bushes (not shown) which fit over pins (not shown) of the hopperunit. On one side of the drum is a belt 16 supported by a pulleyarrangement 17 which in combination with the drum (which provides thedriving force) drives the paper sheets to a position for ejectionthrough the throat 4. The hopper unit includes a baseplate 18 which isslidably movable between two end walls 19 and 20 and the hopperstructure includes a jack plate 21 intended as a support for thebaseplate 18 of the magazine. Lifting mechanism shown schematically at22, comprises an air cylinder controlled by a solenoid valve driving ashaft through a one-way clutch, with another one-way clutch acting as abackstop, although other forms of actuation could be used, and serves toprogressively raise the support plate 21 and with it the magazinebaseplate 18 and a stack of paper resting on the latter, until theuppermost sheet of paper in the magazine reaches a predetermined level,just short of contact with the drum 5. At this predetermined level thetop sheet of paper operates a feeler device 24 to deenergize the liftingmechanism 22 until a drop in the level of the uppermost sheet of paperoccurs, due to withdrawal of individual sheets of paper by the drum hascaused the level to fall by predetermined small amounts sufficient toreverse operation of the feeler device 24. One or more continuouslyoperated blast nozzles schematically indicated at 26 are provided tokeep the uppermost sheet in the magazine in a more or less floatingstate, thereby counteracting any tendency for the second sheet toparticipate in the feed movement of the topmost sheet when this iswithdrawn by the feed movement of the topmost sheet when this withdrawnby the feed drum 5. Suction-type holding foot 25 is provided to retainthe uppermost sheet of the stack in its position in the hopper up to themoment of its withdrawal by the drum 5 at which time the suction isarranged to be disconnected from the device 25.

As shown schematically in FIG. 4 the suction-type holding foot issupplied from a rotor disc valve 27 which is driven mechanically fromthe feed drum 5, to switch from position A to position B for eachrevolution of the drum. in this example during each revolution of thedrum 5 the holding foot 25 is coupled to position A for about a quarterof a revolution and to position B for the rest of the revolution of thedrum. At position A the holding foot 25 is connected to the wiper of atwo-way valve 28 which may be connected either to atmosphere or to avacuum pump indicated at 29 via a shut-off valve 30, whereas at positionB of the rotor disc valve the holding foot 25 is coupled via thisshutoff valve 30 to the vacuum pump 29. The vacuum pump is alsoconnected to the feed drum 5 via another shutoff valve 31. Assuming thetwo shutoff valves to be open as shown in FIG. 4 the operation of theequipment for paper feeding is as follows. The front end of a papersheet is picked up by the feed drum 5, wraps around it and then slidesover its surface as the frictional and suctionholding force availablefrom the holding foot 25 is greater than that available from the drum 5.The rotary disc valve 27 which is synchronized with the feed drumdisconnects the foot from vacuum and vents it to atmosphere at apredetermined time via the two-way solenoid valve 28. This allows thepaper to move forward and out of the hopper. As soon as the tail of thelongest document which it is required to feed has cleared the foot,vacuum is reapplied at the foot and the sheet below is picked up andgripped preventing it from being accidentally drawn forward and holdingit in readiness for the next cycle. If it is required to inhibitfeeding, the vent outlet A of the disc valve 27 is switched fromatmosphere to vacuum by means of the two-way solenoid valve 28. Thesolenoid valve 28 may be operated when the disc valve 27 is coupling thefoot directly to vacuum and its timing is thus not critical. in theinhibit condition vacuum is therefore applied to the foot at all timesand the paper cannot be pulled forward. The shutoff valve 30 is solenoidoperated and may be actuated to cut off all vacuum supply to the footwhen the hopper is not in a loaded condition. The other shutoff valve 31may be operated in accordance with a predetermined program, for cuttingoff vacuum to the feed drum, to reduce the vacuum consumption of themachine.

The energization of the two-way valve may be controlled by a solenoidwhich itself is controlled by a master control device which does notform part of the present invention and which may itself be preferablycontrolled by programming means which may be so arranged as to obtain onthe track at the end of the last module a prearranged sequence of sheetsfrom various hopper positions spaced at regular and substantiallyuniform intervals from each other irrespective of the point of theorigin of each individual sheet.

The device can be used for the programmed assembly of multisheetpublications for example brochures containing a number of illustratedpages intended to be used in all of the number of editions and say onedescriptive page which is available in different languages, a differentone of these being incorporated in each of the various languageeditions. It may also be used for feeding documents to an in-lineprinter, which may be for example intended to add a common overprintingto a sequence of otherwise different sheets and for other more or lessequivalent purposes. Various modifications may be effected withoutdeparting from the basic principle of the invention thus instead ofsupplying documents withdrawn from the top of the magazine hopper totrack arranged above the hopper, the arrangement may be reversed subjectto minor modifications which will be readily appreciated by thoseskilled in the art, to withdraw documents from the bottom of the hopperand feed them from above to a track arranged beneath the hopper.

We claim:

1. Sheet-feeding equipment comprising a conveyor movable along a path, anumber of hopper units spaced along the con veyor path, each hopper unitbeing equipped with a feed drum rotatable about an axis substantiallyperpendicular to the conveyor path and having suction ports in a part ofits circumference for drawing in use, one end of a top sheet away from apile of sheets loaded in the hopper unit, suction foot means againstwhich in use the top sheet is normally held by suction sufficient toresist a tendency for the sheet to be removed by the drum from the pile,a rotor disc valve which is driven at the same angular velocity as thefeed drum, so that during part of a revolution of the feed drum thesuction foot is coupled to a suction supply port and during the rest ofthe revolution it is coupled to a control port, the air pressure atwhich is determined in accordance with the setting of valve means,operable for facilitating the provision at a predetennined instant ofreduced suction at the suction foot, to enable the top sheet to bewithdrawn from the pile as the drum rotates and thereafter to bedelivered through a delivery throat in a direction and at a speedsubstantially similar to the movement maintained on the said track.

2. Sheet-feeding equipment as claimed in claim 1 wherein the controlport is nonnally coupled through the valve means to a vacuum or partialvacuum until the valve means is operated to couple the control port toatmosphere, atmospheric pressure thereafter being applied to the suctionfoot via the rotor disc valve thus removing from the top sheet therestraining force afforded by the reduced air pressure at the vacuumfoot and allowing the sheet, through further rotation of the feed drum,to be carried away from the pile for subsequent ejection through thethroat on to the conveyor track.

3. Sheet-feeding equipment as claimed in claim 2 wherein the valve meanscomprises a two-way valve including solenoid-operating means.

4. Sheet-feeding equipment as claimed in claim 3 wherein the hopper unitincludes a magazine which may be readily in serted into or withdrawnfrom the hopper unit.

5. Sheet-feeding equipment as claimedin claim 4, wherein the conveyortrack is arranged above the magazine with the said drum arranged overthat end of the sheets in the magazine which faces the rearward end ofthe said track so that after passing over one-half of the circumferenceof the said drum this end of each sheet will be ejected first onto thesaid track through the said throat to becomethe leading edge of the eachmagazine includes a baseplate at the lower end of thestack of sheets ina magazine and means for raising the baseplate until the uppennost sheetreaches a predetermined level just below the feed drum whereupon theupward movement is terminated under the control of a detector devicewhich is arranged to switch on a vacuum and to restart the feed movementwhen the level has fallen by a predetermined amount.

7. Sheet-feeding equipmentas claimed in claim 6, wherein the top sheetof the stack which is being picked up at one end by the suction foot andthe next sheet are separated by an air jet which is directed across thetop of the stack to effect separation and to obviate the risk of twosheets being picked up by the drum.

8. Sheet-feeding equipment as claimed in claim 7 wherein thecontinuation of movement of each sheet after its delivery onto the trackis effected by means of driven rollers carried in the track bed againstwhich the sheets are resiliently urged by slightly loaded nondrivencontact rollers.

1. Sheet-feeding equipment comprising a conveyor movable along a path, anumber of hopper units spaced along the conveyor path, each hopper unitbeing equipped with a feed drum rotatable about an axis substantiallyperpendicular to the conveyor path and having suction ports in a part ofits circumference for drawing in use, one end of a top sheet away from apile of sheets loaded in the hopper unit, suction foot means againstwhich in use the top sheet is normally held by suction sufficient toresist a tendency for the sheet to be removed by the drum from the pile,a rotor disc valve which is driven at the same angular velocity as thefeed drum, so that during part of a revolution of the feed drum thesuction foot is coupled to a suction supply port and during the rest ofthe revolution it is coupled to a control port, the air pressure atwhich is determined in accordance with the setting of valve means,operable for facilitating the provision at a predetermined instant ofreduced suction at the suction foot, to enable the top sheet to bewithdrawn from the pile as the drum rotates and thereafter to bedelivered through a delivery throat in a direction and at a speedsubstantially similar to the movement maintained on the said track. 2.Sheet-feeding equipment as claimed in claim 1 wherein the control portis normally coupled through the valve means to a vacuum or partialvacuum until the valve means is operated to couple the control port toatmosphere, atmospheric pressure thereafter being applied to the suctionfoot via the rotor disc valve thus removing from the top sheet therestraining force afforded by the reduced air pressure at the vacuumfoot and allowing the sheet, through further rotation of the feed drum,to be carried away from the pile for subsequent ejection through thethroat on to the conveyor track.
 3. Sheet-feeding equipment as claimedin claim 2 wherein the valve means comprises a two-way valve includingsolenoid-operating means.
 4. Sheet-feeding equipment as claimed in claim3 wherein the hopper unit includes a magazine which may be readilyinserted into or withdrawn from the hopper unit.
 5. Sheet-feedingequipment as claimed in claim 4, wherein the conveyor track is arrangedabove the magazine with the said drum arranged over that end of thesheets in the magazine which faces the rearward end of the said track sothat after passing over one-half of the circumference of the said drumthis end of each sheet will be ejected first onto the said track throughthe said throat to become the leading edge of the sheet during itstravel.
 6. Sheet-feeding equipment as claimed in claim 5, wherein eachmagazine includes a baseplate at the lower end of the stack of sheets ina magazine and means for raising the baseplate until the uppermost sheetreaches a predetermined level just below the feed drum whereupon theupward movement is terminated under the control of a detector devicewhich is arranged to switch on a vacuum and to restart the feed movementwhen the level has fallen by a predetermined amount.
 7. Sheet-feedingequipment as claimed in claim 6, wherein the top sheet of the stackwhich is being picked up at one end by the suction foot and the nextsheet are separated by an air jet which is directed across the top ofthe stack to effect separation and to obviate the risk of two sheetsbeing pickEd up by the drum.
 8. Sheet-feeding equipment as claimed inclaim 7 wherein the continuation of movement of each sheet after itsdelivery onto the track is effected by means of driven rollers carriedin the track bed against which the sheets are resiliently urged byslightly loaded nondriven contact rollers.